Arc-lamp.



in. 896,274. PATENTED AUG. 18, 1908.

G. N; OHAMBBRLIN. ARC LAMP.

APPLICATION FILED DEG.21,1906.

Fig. I.

1 70 Witnesses:

down.

men V GUY N. UHAMBERLIN, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ARC-LAMP.

Application filed December 21, 1906. Serial No. 348,884.

T 0 all whom it may concern:

Be it known that I, GUY N. CHAMBERLIN, a citizen of the United States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and usefu Improvements in Arc-Lamps, of which the following is a specification.

My invention relates to electric arc lamps F and has for its object to improve the same.

In inclosed are lamps the admission of air into the inner globe is restricted so as to prolong the life of the electrodes. A limited supply of 'air is however necessary for effective lighting. In the most common form of arc lamps, namely, that wherein the lower electrode is held stationary and the upper electrode is fed to compensate forthe con sumption of both electrodes, the quantity of air required for effective illumination varies as the arc travels downwards in the globe; more air being required when the are is near the top of the globe than when it is lower Ileretoiore it has been customary to so adjust the means for controlling the air supply that sullicient air may enter the globe at the time the maximum amount is required. Therefore, in such constructions an unnecessarily large amount of air is supplied after the arc has left its extreme upper position and the electrodes are then consumed at an unnecessarily rapid rate.- By my inven tion the air supply is automatically regulated to meet the different conditions existing on account of the downward travel of the are.

To the above end my invention comprises a novel construction and arrangement of parts tobe hereinafter particularly pointed out in the claims.

For a full understanding of the invention and of its various objects and advantages, reference is to be had to the following detailed description taken in connection with the accompanying drawing, wherein Figure 1 is a perspective view of a lamp embodying the present invention in a preferred form, the casing and outer globe being removed to more, clearly show the lamp mechanism; Figs. 2, 3 and 4 are perspective views showing on an enlarged scale the three different parts of" which the gas cap is made;

and Fig. 5 is an enlarged view of a detail.

Reference being had to the drawing, 1 represents anarc lamp of any usual or preferred construction, that illustrated having. a frame Specification of Letters Patent.

the hood and plati'orm together.

Patented. Aug 18, 1908.

made up of a hood or canopy 2, a platform 3, and a central tube or-backbone 4 connecting the platform is supported a gas-cap 5. i

6 and 7 are, respectively, the upper and the lower electrodes, the electrode 6 being slidably arranged within the tube 41 and the electrode 7 being fixed in a holder Si 9 is a regulating magnet which controls the upper electrode in any usual or desired way, as by means of a clutch 9.

10 is a bail for holding the inclosing globe 11 against the under surface of the gascap.

In accordance with my invention, a channel or passage connects the interior of the globe with the atmosphere and means are provided for controlling this channel in such a way that the quantity of air which may be admitted to the globe varies as the are assumes diiierent positions in the globe. This passage may conveniently be formed by constructing the gas-cap in the manner illustrated in an application filed in the name of Richard Fleming, on May 4, 1905, Serial No. 258,796, namely, the gascap may consist of two portions 12 and 13, separated from each other by a thin disk 14; the members 12 and 13 being cored out, so that when theparts are assembled thereis formed in the gas-cap an elongated passage which opens into the globe at one end and into the atmosphere at the other. This passage consists of concentric spiral grooves 16 and 17 in the member 12, and grooves 18 and 19 in the member 13, the two sets of grooves being joined in series with each other by means of an opening 20 in the disk 14 through which the grooves 17 and 18 are made to connnunicatc with each other. The groove 16 communicates at one end with the arc inclosure through an opening 15 in the gasaaap. The. groove 19 opens into atmosphere through the electrode opening 21. Thus, when the lamp is in opera tion, gases may discharge from and air may passage in the gas-cap.

The-passage may be controlled in various ways so as to vary the amount of air admitted into the globe during the operation of the lamp. Thus the parts may conveniently be enter into the globe througlnthe circuitous so proportioned that the gas-cap, in the condition described, provides the minimum sup ply ofair required during the operation .of the lamp. Then, when the are 1s insuch position that more than the minimum amount Beneath of air is required, the character of the passage may be altered. This may of course be done in various ways as, for example, the effective length of the passage between the globe and the atmosphere may be varied. This latter method of controlling the passage 1 have found to be satisfactory. I have also found that good results are obtained by providing only two different efi'ective passage lengths, that is, causing the lamp to operate with one length of passage until the arc has traveled part way down the globe and then increasing the elleetive length of the passage and main taining this increased length during the l'urther operation of the lamp. y

In the embodiment of my invention illustrated, the passage in the gas-cap is tapped at a point intermediate its length and a valve provided for normally opening the passage into the atmosphere at this point and for closing such communication between the passage and the atmosphere when the upper electrode has fed a predetermined distance. this end a short section ol tube 22 is screwed into or otherwise secured to the gas-cap so as to communicate with the groove 1.7. The outer end of the tube is provided with a valve seat 23 arranged to receive a valve 24. This valve is carried upon the lower end of a rod 25 which is connected to or forms an extension of a rod 26 mounted in brackets 27 and 28 on the backbone of the lamp. At the upper end of the rod 26is a finger or rojection 29 which extends into the path of movement of the pin 30 carried by the holder 31 for the upper electrode.

The parts are so arranged that when new electrodes are put in the lamp, the pin on the holder for the upper electrode engages with the linger on the Valve rod and raises the valve off its seat. Therefore, at this time, the groove 17 in the gas-cap communicates with the atmosphere through the short tube 22, and the effective passa e-length between the interiorand exterior o the globe is now shorter than the maximum, consisting only of the groove 16, a ortion of the groove 17, and the tube 22. s the electrodes are consumed the up er electrode and its holder descend gradually, carrying the valve toward its seat, until the electrodes have been partially consumed and it becomes desirable to lengthen the air passage. This occurs-when the arc has descended to the point indicated by the arrow in Fig. 1. The valve now drops into its seat and the end of the tube 23 is closed. During the further operation of the lamp, therefore, the air which enters the globe must pass throughout the entire length of the combined grooves in the gas-cap.

It will of course be understood that in its broad aspects my invention may be embodied in many different forms, and I therefore do not desire to be limited tothe particular form shown, but intend to cover all forms coming within the scope of my invention delined in.the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is,- 1. In an arc lamp, an arc-inclosing globe, means for supplying air to said globe, and means actuated by the feeding movement of an electrode for automatically varying the rate at which air is supplied during the operation of the lamp. y

2. In an arc lamp, an arc-inclosin globe, means for supplying air to said globe, and means for causing the rate at which the air is supplied to be automatically varied after the electrodes have been consumed a predetermined amount.

3. In an arc lamp, an. arc-inclosing globe, means for supplying air to said globe, and means for causing the rate at which air is supplied to be automatically varied alter one of the electrodes has been consumed a predetermined amount 4. In an arc lamp, an arc-inclosing globe having a passage through which air enters the globe, and means actuated by the feeding movement of an electrode fora'utomatically regulating said passage to vary the rate at which air mayentcr the globe,;

5. In an arc lamp, electrodes, an arcinclosing globe, electrode-feedingmeans arranged to cause the position of thea'rc in the globe to vary as the electrodes are consumed, means for supplying air to said globe, and means for automatically varying the rate at which the air is supplied as the'arc changes its-position in the globe. j 1

6. In an arc lamp, electrodes,-an are inclosing globe, electrode-feeding means arranged to cause the position ol the are to vary as the electrodes are consumed, means for supplying air to the globe, and means for automatically changing the rate at which air is supplied when the arc reaches a predetermined position in the globe.

7. In an arc lamp, an arc-inclosing globe having a passage through which air is admitted, and means for automatically varying the ell'cctive length ol" said. passage.

8. In an arc lamp, an arc-inclosing globe having a passage .through which air is allmitted, and means for automatically changing the e'll'ective lengthol" said passage when a predetermined operating condition is reached.

9. In an arc lamp, an arc-inclosing globe having a passage through which air is admitted, and means for automatically changing the effective length of said passage after the electrodes have wasted away a predetermined amount.

10. In an arc lamp, electrodes, an arcinclosing globe having a passage through which air is admitted, electrode-leeding mechanism arranged. to cause the position of the arc to vary as the electrodes are consumed, and means for automatically varying the effective length of said passage when the are reaches apredetermined point.

11. In an arc lamp, electrodes, an arcinclosing globe having a pass e through which air is /admitted, electro e -feeding mechanism arranged to cause the arc to travel downwards in the globe as the electrodes are ct nsurned, and means for automatically shortening the effective length of said passage ,ivhen the arc reaches a predetermined point.

12. In an arc lamp, electrodes, one of which is movable, an arc-inclosing globe .having a passage for the admission of air,

feeding mechanism arranged to cause said movable electrode and the arc to travel downward as the electrodes are consumed,

, and means for automatically shortening the effective length of said passage when the movable electrode has traveled a predeter' mined distance. I

13. In an arc lamp, electrodes, an arciuclosing globe having a passage opening into the surrounding medium,.tliere being an outlet into said medium intermediate the ends of the passage, a valve for controlling said outlet, electrode feeding mechan,

ism arranged to cause the arc to travel downwards 1n the globe as the 'electrodes are consumed, and means for causing said valve to close said outlet when the arc reaches a predetermined position inithe lobe; 14. A gas-cap for inclosecl arc lamps having a passage communicating at its ends respectively with the arc inclosure-and the atmosphere, there being an outlet from said passage intermediate the ends thereof, and i valve for controlling said outlet, and means for actuating said valve. v 40 15. In an inclosed arc lamp, electrodes, a gas-cap having a passage communicating at its ends respectively with the arc inclo- 4 sure and with the atmosphere, electrodefeeding mechanism arranged to cause. the 4'5 arc to travel downwards in the globe as the electrodes are consumed, there being an.

outlet in said passage intermediate the ends thereof, a valve for said outlet, and means for operating said valve to close the said outlet when the arc reaches -.a predetermined position. 3

In witness whereof, I havdhereunto set". my hand this seventeenth day of December; 1906. I;

GUY N. oHAMBERLiN. Witnesses JOHN A. MoMANUs, Jr., PHILIP F. HARRINGTON. 

